The algae blooms in Lake Erie that led to contamination of Toledo’s water supply also occur in Central Indiana reservoirs and waterways, but the fact that Citizens Energy Group draws from multiple sources of water makes such a widespread emergency unlikely in Indianapolis, a utility spokeswoman said.

More than 400,000 people in the Toledo region were scrambling for drinking water since early Saturday when toxins were discovered in a northwestern Ohio treatment plant. People in southeastern Michigan also were told to avoid drinking tap water. Residents today received an “all clear” to resume drinking their water.

If Citizens’ regular water-testing revealed a problem at any of its sources, Holsapple said, Citizens would simply make a quick switch to pull water from its other sources while addressing issues at the problematic area.

“In early July, we treated Eagle Creek to kill an algae bloom,” Holsapple said. “We just drew water elsewhere while doing that.”

The chemicals used to kill an algae bloom do not pose risks to swimmers, she said.

The best means of preventing algae blooms is for residents to stop using fertilizers containing phosphorus, Holsapple said. Runoff containing the common fertilizer component feeds the blooms, she said.